Device for stereoscopic visualization including a stereomicroscope and fiberscope

ABSTRACT

The device for stereoscopic visualization according to the present invention enables an observer to see both an image from a stereomicroscope and an image from a stereoscopic fiberscope without removing his eyes from the eyepieces. The device for stereoscopic visualization may be used in surgical procedures.

TECHNICAL FIELD

The present invention relates to a device for stereoscopic visualizationwhich enables stereoscopic observation of an object. In particular, thepresent invention relates to a device for stereoscopic visualizationwherein the observer can observe a view of the image from astereomicroscope and a view of the image from a stereoscopic fiberscope,without having to remove his eyes from the eyepieces.

BACKGROUND ART

Surgery on the eyes, brain and other areas demands extremely delicatetechniques, and thus, in recent years has been carried out whileemploying a stereomicroscope to observe the affected area.

As shown in FIG. 15, a stereomicroscope has at least a pair of eyepieces1 and a pair of objectives 2, through which a left eye optical path 8land a right eye optical path 8r pass, the left eye optical path 8lcorresponding to the left eye and the right eye optical path 8rcorresponding to the right eye of the observer 7.

Further, the angle defined by the observed object S1 and the opticalaxes of the two objectives 2 is designated as the angle of visibilityα,while the angle defined by the observed object S2 and the optical axesof the two objectives 2 is designated as the angle of visibilityβ. Theangle of visibilityα for observed object S1, which is at a positioncloser to the observer, is larger than angle of visibilityβ. Thedifference between these two angles is designated as the anglevisibility differenceθ.

The observer 7 recognizes the angle visibilityθ difference as thedifference between his distance from observed object S1 and observedobject S2. As a result, the observer is able to view the observed objectstereoscopically.

Endoscopes (fiberscopes), which in general are widely used in medicalexams and treatments, primarily of the digestive system, are increasingin importance. In particular, ultrathin endoscopes of less than 1 mm indiameter have been developed in recent years. These endoscopes can beused not only in the digestive system, but also in areas previously notpossible such as extremely narrow, fine lumen, for example, bloodvessels, mammary glands, pancreatic ducts, inside the eye, and vesselsin the brain.

Accordingly, in delicate surgeries carried out in recent years, astereomicroscope has been employed to observe the entire image of thesurgical area, while an endoscope has been employed for detailedexamination.

However, when performing surgery using an endoscope, the difficulty of adelicate operation is compounded if a sense of distance from the imagecannot be imparted to the observer.

Thus, the ability to visualize an object stereoscopically is necessarywhen employing an endoscope as well. Thus, as in the case of thestereomicroscope described above, a stereoscopic endoscope provided witha two system fiberscope for the left and right eyes of the observer wasdeveloped.

The principle behind one example of this device will now be explainedwith reference to FIG. 16. The stereoscopic endoscope explained in FIG.16 is provided with eyepieces 3, guided optical paths 4 comprising anoptical fiber, objectives 5 and a light guide 6 for the purpose ofillumination. Left eye optical path 8l and right eye optical path 8r,corresponding to the left and right eyes of the observer 7, pass througheyepieces 3, guided optical paths 4 and objectives 5.

The angle visibility differenceθ between the angle of visibilityαdefined by the Observed object S1 and the optical axes of the twoobjectives 5 and the angle of visibilityβ defined by the observed objectS2 and the optical axes of the two objectives 5 is recognized by theobserver 7 as the difference in his distance from observed object S1 andobserved object S2, thus enabling stereoscopic visualization.

The combined employment of a stereomicroscope and a stereoscopicendoscope has been increasing.

However, in order to use a stereoscopic endoscope after using astereomicroscope, the observer must shift to the stereoscopic endoscopeby removing his eyes from the stereomicroscope for a time. Conversely,in order to use a stereomicroscope after using a stereoscopic endoscope,the observer must remove his eyes from the stereoscopic endoscope for atime in order to look into the stereomicroscope. For this reason, inorder to use a stereomicroscope and a stereoscopic endoscope together,the eyes must be moved between the two devices, which is bothersome.Moreover, each time the eyes move from one device to the other, acertain amount of time must be required for the field of vision andfocus to readjust. Thus, the surgery procedure is lengthened by the timerequired to shift between devices and for vision adjustment, increasingthe stress on the surgeon.

DISCLOSURE OF INVENTION

The present invention was conceived in order to resolve theaforementioned problems, and has as an object the provision of a devicefor stereoscopic visualization which enables observation through astereomicroscope and observation through a stereoscopic endoscope to becarried out without requiring the observer to shift his eyes. In oneaspect of the present invention, the optical path of the eyepiece isjoined with one of either the optical path of the stereomicroscope orthe optical path of the stereoscopic fiberscope by means of theoperation of an optical path switcher, so that the eyes are neverremoved from the eyepieces. Thus, by means of a simple operation, theobserver can alternately view the image from a stereomicroscope and theimage from a stereoscopic fiberscope.

Further, in another aspect of the present invention, a reflecting mirrorwhich transmits light rays from the stereoscopic fiberscope to theeyepiece is provided along the optical path which joins the objectiveand the eyepiece of the stereomicroscope. As a result, the image fromthe stereoscopic fiberscope can be formed inside the image from thestereomicroscope. Accordingly, the observer does not need to remove hiseyes from the eyepieces, but is able to simultaneously observe the imagefrom the stereomicroscope and the image from the stereoscopicfiberscope.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fiberscope.

FIG. 3 is a diagram of the optical path in one embodiment of the presentinvention.

FIG. 4 is a front view showing another embodiment of the presentinvention.

FIG. 5 is a diagram of the optical path of the embodiment of the presentinvention shown in FIG. 4.

FIG. 6 is a plan view showing the image shown in the eyepieces.

FIG. 7 is a plan view showing the image recognized by the observer.

FIG. 8 is a diagram of the optical path provided for explaining theimage aligner.

FIG. 9 is view in lateral cross-section showing the left half of theimage aligner.

FIG. 10 is a view in lateral cross-section showing another example ofthe image aligner.

FIG. 11 is a plan view showing an example of an image.

FIG. 12 is a plan view showing an example of an image.

FIG. 13 is a plan view showing an example of an image.

FIG. 14 is a plan view showing an example of an image.

FIG. 15 is a diagram of an optical path in a conventionalstereomicroscope.

FIG. 16 is a diagram of an optical path in a conventional endoscope.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

FIG. 1 shows one embodiment of the device for stereoscopic visualizationof the present invention. This device 10 is provided with eyepieces 11,which has a pair of optical paths 8l,8r corresponding respectively tothe left and right eyes of an observer 7, a stereomicroscope objective12, a stereoscopic fiberscope objective 13, and an optical path switcher14. The respective pairs of optical paths of stereomicroscope objective12 and stereoscopic fiberscope objective 13 can be freely changed bymeans of optical path switcher 14, with one pair of the optical pathsjoining with the pair of optical paths of eyepieces 11.

Optical path switcher 14 internally houses a pair of reflecting mirrors15l,15r. These reflecting mirrors 15l,15r, which are coupled andrevolve, are driven by a foot switch 16 so that each can simultaneouslyswitch the left eye optical path 8l and the right eye optical path 8r toeither the stereomicroscope objective or the stereoscopic fiberscopeobjective.

Respective image aligners 18 for left eye optical path 8l and right eyeoptical path 8r are provided between optical path switcher 14 andstereoscopic fiberscope objective 13, adjacent to optical path switcher14. The image aligners 18 and stereoscopic fiberscope objective 13 arejoined by flexible image fibers 17l,17r corresponding respectively tothe left eye optical path and the right eye optical path. Image aligners18 are designed so that the position, orientation, and focus of each ofthe left and right images can be adjusted by moving or rotating theoptical axes of the image fibers connected thereto.

Stereoscopic fiberscope objective 13 has image fibers 17l,17r connectedto the objective lens at its tip, and light guides 21 disposed parallelto the image fibers.

A cross-section of the fiberscope, in which image fibers 17l,17r andlight guides 21 form a bundle, is shown in FIG. 2. Image fiber 17l, usedfor the left eye optical path, image fiber 17r, used for the right eyeoptical path, and a plurality of light guides 21,21 . . . are wrappedtogether inside fiberscope 26. Cylindrical spacers 25,25 are disposed infiberscope 26 shown in FIG. 2, for separating image fiber 17l and imagefiber 17r. Light guides are also disposed inside these spacers 25.

Light guides 21 are connected to fiberscope light source 22.Illuminating light from fiberscope light source 22 which has passedthrough light guide 21 illuminates an object Sf observed with thestereoscopic fiberscope.

It is desirable to provide an illuminating lens to the tip of lightguides 21 in the same way that an objective lens is provided to the tipof image fibers 17l,17r.

Each image fiber 17l,17r comprises an image circle, whereinapproximately 1,500 to 50,000 GeO2-SiO2 cores as a quartz glass fiberare disposed at fixed intervals inside a common clad of SiO2 or SiO2-F,and SiO2 jacket which covers this image circle. Further, the entireimage fiber is covered with a resin such as a silicon resin or a UVhardening resin. The diameter of the cores is 2 μm to 10 μm and thediameter of the image fiber is 125 μm to 2000 μm, so that the diameterof the image fiber is 135 μm to 3000 μm when the protective coveringlayer is included.

Each of these image fibers 17l,17r is housed in a guide tube whichguides the image fiber. Stainless steel or a resin such as polyimide,fluorinated ethylene propylene, ETFE, polytetrafluoroethylene,polyethylene, polypropylene, polyvinyl or the like may be employed asthe material for the guide tube. The inner diameter of the guide tube is135 μm to 3,500 μm, while the outer diameter is 150 μm to 4,000 μm.

The light guide is a fiber consisting of a multicomponent glass, quartzglass, plastic or the like, with a diameter of 10 μm to 2,000 μm.

The spacer consists of stainless steel, quartz glass or a resin such aspolyimide, fluorinated ethylene propylene, ETFE,polytetrafluoroethylene, polyethylene, polypropylene, polyvinyl or thelike, and has a diameter of 100 μm to 2,000 μm. From 0 to 10,000 lightguides are inserted in this cylindrical spacer. In addition, this spaceris not absolutely necessary, but may be eliminated by fixing together aspecific number of light guides. Further, a pair of image fibers aredisposed inside a coated tube, to be explained below, so as to mutuallycontact with one another. Provided their deflection can be controlled,the spacers may be omitted.

These image fibers, light guides and the like are disposed inside andcovered by a tube consisting of stainless steel or a resin likepolyimide or polytetrafluoroethylene. The thickness of this coated tubeis 0.3 to 10 mm.

The length of the fiberscope is 0.2 to 10 m in total, with the length ofthe inserted portion being 10 to 350 mm.

The thus-described fiberscope is formed in the following way.

First, rod lenses which bring together image formation characteristics(angle of view, focus position, contrast, size, etc.) are attached tothe tips of the image fibers which bring together transmissioncharacteristics (contrast, length of radius, etc.). From among thoseproduced, a pair of image fibers with attached rod lens which bringtogether the transmission and image formation characteristics areselected. Then, a pair of rounded light guide fibers, wherein the lightguides either fill a cylindrical spacer or the light guides are fixedtogether at the tips with an adhesive or the like, is formed, with thetips being adhered together.

Next, the pair of guide tubes which guide the image fibers are disposedinside the coated tube. Further, a pair of spacers is also disposedinside the coated tube, with light guides inserted to fill the spacesthereof. Then, the entire structure is sealed.

The tip is then polished, and the image fiber with its attached lens isinserted into the guide tube, and sealed.

The following is a concrete example of a fiberscope which satisfiesthese conditions.

The entire length of the fiberscope employed here is 2.0 m, with thelength of the inserted portion being 30 mm. The coated tube employedhere is of stainless steel and has an outer diameter of 1.0 mm, with aninner diameter of 0.9 mm.

A polyimide tube with an outer diameter of 0.4 mm and an inner diameterof 0.36 mm is employed for each image fiber 17l,17r. Further, theseimage fibers have 5,000 pixels with a pixel diameter of 300 μm;SiO2-GeO2 is employed for the cores which compose the pixels, with theclad consisting of SiO2-F. The image fibers are provided with aprotective resin layer consisting of a UV hardening resin of thickness25 μm.

A polyimide tube of outer diameter 0.3 mm and inner diameter 0.25 mm isemployed for the cylindrical spacers.

A multicomponent glass fiber of diameter 30 μm is employed for thelightguides. Out of 194 lightguides, 37 lightguides are used to fill theinside of each spacer, with the remaining 120 lightguides used to fillthe outside space.

For example, an object can be observed in the following way employing adevice for stereoscopic visualization of the above construction. First,the optical path switcher 14 is set to stereomicroscope objective 12,and the left eye optical path 8l at eyepiece 11 and the left eye opticalpath 9l of the stereomicroscope objective 12 are joined, while the righteye optical path 8r of eyepiece 11 and the right eye optical path 9r ofthe stereomicroscope objective 12 are joined. Accordingly, observer 7recognizes an image of observed object Sm from the stereomicroscope.

Further, as observed object Sm is observed through eyepieces 11, thefocus of stereomicroscope main body 19, which includes eyepieces 11 andstereomicroscope objective 12, is adjusted by turning focus adjustmentknob 20.

Next, optical path switcher 14 is switched to stereoscopic fiberscopeobjective 13. In other words, by changing the angle of reflectingmirrors 15l,15r of optical path switcher 14, the left eye optical path8l at eyepiece 11 and the image fiber 17l are joined, while the righteye optical path 8r at eyepiece 11 and the image fiber 17r are joined.At the same time, left eye optical path 9l and right eye optical path 9rfrom the stereomicroscope objective are blocked by reflecting mirrors15l,15r.

Fiberscope light source 22 is turned on, and the observed object Sf isilluminated via lightguides 21.

Thus, the observer recognizes the observed object Sf from thestereoscopic fiberscope.

Further, when optical path switcher 14 is switched from thestereomicroscope to the stereoscopic fiberscope objective 13, the focusand relative disposition of the image observed will be disrupted. Inorder to avoid this, one or both of the left and right image aligners 18can be adjusted in advance, thus eliminating the need for adjustmentlater.

Further, it makes no difference whether the observed object Sf is in thefield of view of the stereomicroscope main body 19 or not. In otherwords, if observed object Sf is included in the observed object Sm, thenobservation with the stereoscopic fiberscope can be carried out byenlarging a portion of the observed object Sm. Further, if observedobject Sf is not included in observed object Sm, then the area which isnot observed with the stereomicroscope can be observed with thestereoscopic fiberscope.

In the above-described device for stereoscopic visualization, theobserver 7, with his eyes placed against the eyepieces 11, operates thefoot switch 16 with his foot to switch between the image from thestereomicroscope and the image from the stereoscopic fiberscope.Accordingly, the hands are not hampered in the switching operation, andthe eyes do not have to be removed from the eyepieces 11. Thus,observation of either object Sm or object Sf can be carried out promptlyat any time.

In particular, the image from the stereomicroscope and the image fromthe stereoscopic fiberscope can be viewed without requiring a highdegree of electrical conversion employing an LCD or the like.

The preceding embodiment will now be explained further employing theoptical path system diagram shown in FIG. 3.

Bidirectional reflected light from observed object Sm is separated andreceived at objective lens 12. Light from the image respectively passesthrough left eye optical path 9l and right eye optical path 9r at theobjectives, and then passes through an erected relay optical system 11awhich has a plurality of lens, etc. Then the light from the image passesthrough the left eye optical path 8l and the right eye optical path 8rof eyepieces 11. In this state, the reflective lens 15l,15r of theoptical path switcher are both parallel to the optical path. The lightfrom the image from objective lenses 12 is not blocked by optical pathswitcher 14, but proceeds directly to eyepieces 11. Observer 7 thusobserves object Sm as a stereoscopic image.

When optical path switcher 14 is switched, reflecting mirrors 15l,15rblock the optical paths 9l,9r from the stereomicroscope objective. Atthe same time, they reflect light from the image incidenting from thestereoscopic fiberscope objective 13 via image fibers 17l,17r, andtransmit the light to eyepieces 11 via erected relay optical system 11a.

Observed object Sf is illuminated with light irradiated fromilluminating lens 23 via light guides 21 which are disposed inside thestereoscopic fiberscope parallel to each image fiber 17l,17r andpreferably comprise a plurality of optical fibers. Further, thisreflected light is received as light from left and right images byobjective lenses 24 which are attached respectively to the ends of eachimage fiber 17l,17r. The reflected light is then transmitted to theimage aligners 18 by image fibers 17l,17r for the left eye optical path8l and right eye optical path 8r respectively. It is preferable thatthese image fibers 17l,17r be formed as respective fiber bundles fortransmitting images, and be image fibers which are multicore typeoptical fibers so that a very small diameter can be obtained.

The light from the left and right images transmitted via image fibers17l,17r respectively can undergo left and right asymmtrical refractionor rotation. Thus, if this light is received at eyepieces 11 which arecombined with stereomicroscope objective 12, the image is not adjustedwith respect to a position or orientation that will definitely enableobservation of a stereoscopic image. Accordingly, the incorrect positionor orientation of the light from the left and right images is adjustedusing image aligners 18, the reflecting mirrors and the like, prior tobeing transmitted to optical path switcher 14. Image aligners 18 areprovided to the respective output terminals of image fibers 17l,17r, andcan move the output terminals in the direction of the optical path (z)and in the two directions (x,y) perpendicular to (z). Further, imagealigners 18 are designed so that they can be fixed in position byproviding a rotation R. Further, adjustment in the x and y directionscan also be carried out by means of the reflecting mirrors. Thus, bythese means, adjustment can be performed to enable observation of thelight from image from the stereoscopic fiberscope objective 13 as astereoscopic image. Provided that there is no change in the scope, theadjustment of image aligners 18 does not need to be carried out duringobservation.

The light of the image which is erected on the left and right by imagealigners 18 is reflected respectively at reflecting mirrors 15 via imagefiber relay lens 14a, reaches eyepiece 11 via erected relay opticalsystem 11a, and is observed by the observer 7 as a stereoscopic image.

Optical path switcher 14 employs reflecting mirrors in the aboveembodiment, but is not restricted thereto. For example, half-mirrors orprisms may also be used. Further, the switching of the optical paths canbe carried out by rotating the reflecting mirrors, half-mirrors, prismsor the like around an axis perpendicular to the optical paths asdescribed above. However, in addition, a solenoid or the like may alsobe employed as a driving means to move the reflecting mirrors or thelike into and out of transsection with the optical paths.

Further, in the case where a half-mirror or small mirror is employed,switching may be accomplished without requiring a drive system byemploying a method wherein either the light incidenting on thestereomicroscope objective or the light incidenting on the stereoscopicfiberscope objective is blocked.

While only a single observer was present in the preceding embodiment,the present invention's device for stereoscopic visualization is notlimited thereto. For example, each optical path 8l,8r between eyepieces11 and erected relay optical system 11a can be separated into 2 opticalpaths. One of the separated optical paths is joined to eyepieces 11, andthe other separated optical path is joined to another set of eyepieces.By this means, a plurality of observers can view an image with thedevice for stereoscopic visualization. Further, the other separatedoptical path can be connected to a TV camera, with the left and rightimages being alternately shown on a monitor. Then, by applying a lenswith an electric shutter which opens and closes alternately on the leftand right in synchronization with this, the image on the monitor can beobserved. In this case, then, not only the surgeons, but any number ofpeople can simultaneously observe the stereoscopic image.

The aligners 18 will now be explained in greater detail.

As shown in FIG. 8, when left eye optical path 8l and right eye opticalpath 8r which pass through eyepieces 11 are joined with left eye opticalpath 9l and right eye optical path 9r from objective lens 12 of thestereomicroscope by means of the driving of reflecting mirrors 15l,15r,then left eye optical path 8l and right eye optical path 8r come incontact with left eye optical path image fiber 17l and the right eyeoptical path image fiber 17r of the stereoscopic fiberscope.

While there is no problem in the connection of optical paths 8l,8r whichpass through eyepieces 11 with each of the optical paths 9l,9r from theobjective lens 12 of the stereomicroscope, distortion in the position ororientation of the image may arise when optical paths 8l,8r which passthrough eyepieces 11 are connected to the optical paths of thestereoscopic fiberscope. Thus, adjustment is carried out using imagealigners 18 or reflecting mirrors 15l,15r. In image aligners 18, focusand optical axis adjustments are carried by each of the lens 38,38 . . ., while at prism 36, left-right reversal of the image is performed.

A compositional member such as shown in FIG. 9 is used for image aligner18. In the case of this device, light from the image which has enteredimage aligners 18 from image fiber 17l is adjusted to the optimalposition and orientation by extending or rotating optical axisadjustment cell 40, which is equipped with a lens 38, and by theleft-right reversal of the light at a prism 36 through which it ispassed. This light from the image is then transmitted to the eyepieces.

Further, as shown in FIG. 10, by employing an image fiber connectionmethod, the optical axis from the image fiber can also be adjusted. Inother words, the light from image fiber 17l is incidented from below,and passes through the lens. Then, it undergoes left-right reversal atreflecting mirrors 27.

By forming this type of image aligner, which is connected to afiberscope and is attached to a stereomicroscope, as a single unit,attachment of a variety of commonly used stereomicroscopes is possible,widening the application thereof.

Embodiment 2

Further, a device for stereoscopic visualization can be composed asshown in FIGS. 4 and 5. In this device, reflecting mirrors 28,28 whichare provided along the optical path from the stereoscopic fiberscope areprovided along optical paths 30l,30r which join eyepieces 11 and theobjective 12 of the stereomicroscope. In this case, the device isdesigned so optical paths 30l,30r are not completely blocked byreflecting mirrors 28.

This device is formed so that images 33l,33r from the fiberscope areplaced into the images 32l,32r of the stereomicroscope in the left andright eyepieces 11, as shown in FIG. 6. Accordingly, when the sameobject is observed with the stereomicroscope and the fiberscope, theobserver sees a portion of he image 32 from the stereomicroscope in theimage 33 from the fiberscope, as is shown in FIG. 7.

Additionally, it is noted here that half-mirrors may also be employed inplace of the reflecting mirrors.

Further, the position of image 33 from the fiberscope in image 32 fromthe stereomicroscope can be adjusted by means of the image aligner orthe inclination of reflecting mirror 28.

In order to observe the image from the stereoscopic fiberscope,illumination from a light guide provided to the stereoscopic fiberscopeis necessary. Accordingly, by stopping the illumination from the lightguide, image 33 from the fiberscope disappears, and the observer seesonly image 32 from the stereomicroscope. In other words, by manipulatingthe light guide, the image from the fiberscope can be "turned on andoff". Further, by placing or removing a blocking cap on the tip of thestereoscopic fiberscope objective, the image from the stereoscopicfiberscope can be "turned on and off".

When a reflecting mirror 28 is provided to the portion of thestereomicroscope inside the optical path 30, the field of vision of theentire object does not change, but the quantity of light decreases.Accordingly, it is desirable to provide an object light source 42 forilluminating the observed object at objective 12 of thestereomicroscope. In this case, it is desirable to lower the degree ofillumination so that light does not strike the position of image 33 fromthe stereoscopic fiberscope or its surrounding area. Image 33 from thestereoscopic fiberscope is generally darker compared with image 32 fromthe stereomicroscope. Thus, in order to make the image 33 from thestereomicroscope clearer, the area around the image should be darkened.

For example, as shown in FIG. 11, only the position of image 33 from thestereoscopic fiberscope and its periphery 44 are darkened in image 32from the stereomicroscope. Further, as shown in FIGS. 12, 13, and 14, itis desirable to darken areas 46, 48, 50 which form the image 33 of thestereoscopic fiberscope.

As a method to darken the area around the position of the image from thestereoscopic fiberscope, it is preferable to provide to object lightsource 42 a mask for blocking the light from object light source 42 fromilluminating that position.

Further, when the amount of light of the image from the stereoscopicfiberscope is considerably less compared to the amount of light from theimage from the stereomicroscope and the image from the stereoscopicfiberscope cannot be observed because the image therefrom is not formedin the dark area, the object light source 42 of the stereomicroscope,and not the fiberscope light source 22, is manipulated. Then, on/offcontrol of the formation of the image 33 from the stereoscopicfiberscope inside image 32 from the stereomicroscope can also be carriedout by means of whether or not the periphery of the image formed fromthe stereoscopic fiberscope is darkened. For example, on/off control ofthe formation of the image from stereoscopic fiberscope 33 inside image32 from the stereomicroscope can be carried by attaching or removing themask.

Further, the amount of light of the image from the stereomicroscope isinfluenced by the area of the reflecting mirror 28 of the optical path30. Thus, the control of the increase or decrease in the amount of lightcan be carried out by moving reflecting mirror 28 from the optical path30.

In the device for stereoscopic visualization having the structure shownin FIGS. 4 and 5, the observer can view the image 32 from thestereomicroscope and the image 33 from the stereoscopic fiberscopesimultaneously. Accordingly, if the observer is viewing the image fromthe stereomicroscope, and then wishes to view the image from thestereoscopic fiberscope, he need not remove his eyes from thestereomicroscope to do so.

In particular, this device for stereoscopic visualization enables theformation of image from a stereoscopic fiberscope inside the image froma stereomicroscope by means of an optical method alone, and not by theemployment of an electronic circuit. Thus, the device is simple,accurate and can be achieved at low cost.

Industrial Applicability

The device for stereoscopic visualization according to the presentinvention enables an observer to quickly switch, between orsimultaneously view, an image from a stereomicroscope objective and animage from a stereoscopic fiberscope objective, without removing hiseyes from the eyepieces. Accordingly, a surgical procedure can becarried out on an affected area while observing images of the areaobtained from a stereomicroscope and a stereoscopic fiberscope.

We claim:
 1. A device for stereoscopic visualization comprising:aneyepiece having optical paths respectively corresponding to a left eyeand a right eye of an observer; a stereomicroscope including astereomicroscope objective along the optical paths of the eyepiece; astereoscopic fiberscope including a stereoscopic fiberscope objective;and reflecting mirrors disposed on the optical paths of the eyepiece andconnecting the eyepiece to the stereoscopic fiberscope objective andwherein the reflecting mirrors are disposed in a portion of the opticalpaths connecting the eyepiece to the stereomicroscope objective toreflect image beams from the stereoscopic fiberscope parallel to andinside image beams from the stereomicroscope objective to thereby forman image from the stereoscopic fiberscope in a portion of an image fromthe stereomicroscope.
 2. The device according to claim 1, wherein theimage from the stereoscopic fiberscope is formed in a darkened portionof the image from the stereomicroscope.
 3. A device for stereoscopicvisualization comprising:an eyepiece having an optical path; astereomicroscope including a stereomicroscope objective along theoptical path of the eyepiece; a fiberscope including a fiberscopeobjective; and a reflecting mirror disposed on the optical path of theeyepiece and connecting the eyepiece to the fiberscope objective andwherein the reflecting mirror is disposed in a portion of the opticalpath connecting the eyepiece to the stereomicroscope objective toreflect image beams from the fiberscope parallel to and inside imagebeams from the stereomicroscope objective to thereby form an image fromthe fiberscope in a portion of an image from the stereomicroscope.